This paper takes part in the series essay competition of “great science” of Recordunkown.
The earth is a planet of life, and human beings are the only intelligent life on this planet. The reason why human beings can become intelligent life, stand at the top of the biological chain and become the overlord of the earth. From the macro point of view, it is because human beings have a developed brain, while from the micro point of view, it is because human beings are basically huge and complex.
After entering the era of science and technology, life science has also ushered in a period of rapid development, and the mysteries of life are constantly studied and explored. In particular, the mystery of human is the focus of scientists’ research. Through research, we know why human beings are different from men and women, and how human beings reproduce.
I believe you started to contact biology when you were in junior high school. At that time, you already understood why there were differences between men and women. In terms of gene, male is composed of XY chromosome, while female is composed of XX chromosome. Chromosome is a specific form of DNA in eukaryotic cells during mitosis or meiosis. In the nucleus, DNA is tightly coiled around proteins called histones and packaged into a linear structure.
Human chromosomes can be divided into two types: autosomal (somatic) and sex (allogeneic). Some genetic characteristics are related to a person’s sex and are transmitted through sex chromosomes. The autosomal therefore contains the rest of the genetic information. The replication, mitosis and meiosis of autosomal and sex chromosomes are consistent. Human cells have 23 pairs of chromosomes (22 pairs of autosomes and one pair of sex chromosomes), that is, each cell has 46 chromatids. In addition, human cells have hundreds of copies of mitochondrial chromosomes.
Chromosomes contain all the information of human beings, which is the biggest secret in human body. Therefore, scientists have been deciphering the genes in these chromosomes, hoping to get all the gene codes of human beings. Once human beings master all the gene codes, it means that we have solved the mystery of life, and human beings will usher in a new life stage.
The male and female characteristics of human beings are determined by sex chromosomes, that is, the male is XY chromosome, the female is XX chromosome, and the Y chromosome is the unique characteristic of men. Many external manifestations of men and women are determined by these two types of chromosomes, in which the Y chromosome is more important. But if one day, the unique Y chromosome of men disappears, what will happen?
Maybe someone will say, how can Y chromosome disappear? If it does disappear, doesn’t that mean men will disappear? What about human reproduction? But in fact, life is the most mysterious thing in the universe, and anything that happens in the evolution of life can happen.
Professor Jennie, a geneticist from Australia, has put forward a rather bold point of view. According to her, the male specific Y chromosome will disappear forever in millions of years, and new races will appear and replace men. Once her statement was published, it immediately attracted the attention of the whole world.
Why did Professor Jenny make such a bold point? Is it pure guess or scientific basis? According to Professor Jennie’s experimental research, the Y chromosome, which determines male characteristics, is gradually degenerating and disappearing over time through continuous genetic variation. The evolution of the human body is determined by genes, and the genes in the human body are not always the same, but often mutated.
There will be genetic differences between people of 10000 years and people of today, which can be seen from their appearance. Ten thousand years later, human beings will certainly be different from today’s in terms of gene. The reason is that the gene is constantly mutating and mutating. In fact, it is also a kind of evolution of life. If the gene remains unchanged, life will not evolve and evolve, nor will it evolve to a higher life.
Human ancestors can be shared from chimpanzees millions of years ago. It is precisely because of a genetic mutation at a certain time that this part of the isolated genes eventually evolved into humans. So millions of years later, human genes may mutate again. What will human become?
It is in the experimental research that Professor Jennie found that the Y chromosome is degenerating step by step, and it is possible that it will disappear in millions of years. At that time, the human gene pool will lose Y chromosome, from 46 to 45. Some people may have said, if there is no Y chromosome, does that mean that men will disappear? Of course not. Scientists believe that even if the Y chromosome gradually falls off and disappears after millions of years, men will not disappear, except that there will be XX chromosome in the male genome at that time.
Isn’t this gene sequence the same as the XX chromosome in women? It looks the same, but it will be different. And this kind of men can also be called new race, with male characteristics, but may lose the ability to reproduce. That is to say, in the future, due to the degeneration and disappearance of Y chromosome, XX male will appear.
Some people may think that XX male will appear only after millions of years, but in fact, according to the research of scientists, there may be a very small number of such men born in modern society, but the number is very small, and we have not found it. So what are the characteristics of XX men?
Since the male XY chromosome has become the XX chromosome, the external performance naturally tends to be more female, such as better skin, no beard or very little beard. Character will be biased towards women, we commonly known as the Niang gun. I believe that this kind of man has been seen in modern society. Of course, it’s not that he is more feminine. This person has become XX chromosome. It just tells us that men show more female characteristics, which indicates that the Y chromosome has obviously degenerated at the somatic gene level.
Some people may worry that if the future really turns out to be what Professor Jenny predicted, how will human beings reproduce and continue? In fact, there is no need to worry about this. The continuous mutation and variation of human genes is also the continuous improvement and evolution process of life level. No matter how the human gene evolves, the ability of reproduction will not disappear. It’s just that millions of years from now, the way humans reproduce may be very different.
Even if the Y chromosome disappears in the future, we don’t have to worry about the disappearance of men. Only the co-existence of men and women can form our perfect human world. Human civilization can not continue to develop without men or women. However, men in the future may gradually lose the masculine and domineering side of modern men, and become more and more gentle, with better skin and appearance.
Of course, this is only the result of natural evolution that scientists guess. If human beings do not have the development of science and technology, maybe the direction of gene evolution in millions of years will be basically determined. However, the intervention of science and technology will make a lot of things uncertain. The direction of human gene evolution in the future may be forcibly intervened by means of science and technology. Therefore, it is still unknown whether the disappearance of Y chromosome under normal circumstances will happen millions of years later.
Guys, what do you think of this? Welcome to leave a message below to discuss and express your opinions.